Bis-PEG7-acid

Bis-PEG7-acid, is designed to provide a flexible, hydrophilic connection between a ligand and an E3-recruiting module, supporting productive ternary complex formation. Its polyethylene glycol–based architecture helps reduce non-specific interactions and can improve aqueous handling during PROTAC synthesis and downstream assays. The linker’s functional acid enables robust conjugation strategies commonly used in targeted protein degradation workflows; detailed structural and synthetic considerations are provided below.

Structure: Bis-PEG7-acid is a PEG-based bis-functional linker featuring an oligomeric polyethylene glycol backbone terminated by carboxylic acid groups. It contains ether linkages characteristic of PEG chains and presents flexible conformational freedom, contributing to water compatibility and reduced steric bias at the conjugation sites.

Reactivity: The terminal carboxylic acids are suitable for amide-bond formation with amine-bearing ligands under standard peptide-coupling chemistries. Typical approaches use carbodiimide or uronium-type coupling reagents with a base in polar aprotic solvents, enabling activation of the acid followed by nucleophilic acyl substitution. Reaction conditions are commonly optimized to preserve ligand integrity and minimize side reactions such as hydrolysis.